Snowmobiles are designed to ride primarily upon snow or ice, and, to this end, are provided with a pair of skis pivotally mounted adjacent the fore end of the snowmobile for gliding across the surface of the snow or ice. An endless drive track is disposed typically medially and rearwardly under the body of the snowmobile and aft of the skis. Typically, the skis are provided with a runner made out of carbide or other suitable material that runs along at least a portion of the bottom surface of the ski to keep the snowmobile travelling along a track.
Although quite useful and efficient in their intended environment, conventional snowmobiles are not well-suited for being driven across rougher surfaces such as pavement, concrete, gravel or the like deprived of snow or ice. When the skis of conventional snowmobiles are driven across such non-snow surfaces, they are relatively rapidly subjected to excessive wear. Accordingly, for example, the carbide runners may require more frequent replacement. Furthermore, when a conventional snowmobile is driven across a non-snow surface, it becomes relatively difficult to steer since the skis lose much of their usefulness.
In order to increase the versatility of conventional snowmobiles by circumventing some of the hereinabove-mentioned disadvantages, some wheel units attachable to snowmobile skis have been developed. However, the snowmobile wheel units shown in the prior art suffer from numerous drawbacks. For example, some prior art wheel units are relatively complex and, hence, relatively expensive. Furthermore, such prior wheel units often suffer from being mechanical failure and, as such, are considered unreliable.
Also, some prior art units require manual skill and/or strength in order for the wheel to be deployed and/or retracted. Furthermore, some prior art wheel units suffer from being unprotected against relatively commonly encountered obstacles and are, hence, subject to being damaged during use of the snowmobile.
Accordingly, there exists a need for an improved snowmobile wheel unit.